Heart Disease (Hypertrophic Cardiomyopathy) in Cats

Treatment

If there is a diagnosis of HCM, your cat will be hospitalized for appropriate care, especially if it is suffering from congestive heart failure, a common outcome of this disease. Your cat will be placed in a quiet environment to minimize stress, and if it is having trouble breathing it will be given oxygen therapy. If your cat’s body temperature is low, your veterinarian will warm the cat in blankets to gently raise the body temperature.

There are several possible medications that can be used to treat hypertrophic cardiomyopathy:

Diltiazim to slow the heart rate, treat irregular heart beats, and possibly reduce the enlargement in the left ventricle

Beta blockers to slow the heart rate, correct irregular heart beats, and control blockage of the blood flow. These are not used if the cat has congestive heart failure

Ace inhibitors, in cases with congestive heart failure, to improve the flow through the ventricle

Aspirin to decrease risk of blood clots

Warfarin to prevent blood clotting

Furosemide (diuretic) to remove excess fluid from the body

Spironolactone (a diuretic used sometimes in conjunction with furosemide) for cats with congestive heart failure

Nitroglycerin ointment, to improve flow by dilating (opening) the ventricle and arteries

Living and Management

The cat should be put on a sodium-restricted diet, especially if there is congestive heart failure, to keep the pressure in the blood stable. Providing a quiet and safe space for your cat, away from other pets and active children, is important to its recovery. Environmental stress may activate the nervous system, placing excess stress on the already overstressed left ventricle, and possibly leading to heart failure.

You will need to monitor your cat closely during the recovery period, watching for difficulty breathing, lethargy, weakness, lack of appetite, and painful hind-limb weakness or paralysis. If your cat is being treated with warfarin, its blood will need to be tested to determine whether the drug is effectively decreasing the likelihood of a blood clot. Use of warfarin can also lead to uncontrolled bleeding and bruising. You will need to take care that your cat is kept from activities that may lead to injury while it is on this drug. If your cat is taking an ACE inhibitor, or spironolactone, kidney function and electrolytes will need to be monitored. After six months, a repeat ultrasound examination of the heart will be required to determine progress, and whether further treatment will be required.